Recently, with an increase in storage capacity and an increase in data recording/reproducing speed, optical disk media have attracted a lot of attention not only as external memories for computers but also as media for image processing, and medium automatic interchange apparatus (hereinafter referred to as auto-changers) capable of managing and processing mass data have been marketed Besides, in recent years, a small-sized auto-changer has been demanded in view of its installation space, and an auto-changer that stores plural media disposed on trays to improve storage efficiency as well as handling simplicity has been proposed.
Hereinafter, a conventional magazine system auto-changer will be described with reference to FIGS. 7 and 8.
FIG. 7 shows a conventional auto-changer. Reference numeral 1 designates a tray carrier unit that takes a tray 8, on which a medium (not shown) is disposed, from a magazine 2, and moves in the arrow a direction to send the tray onto a drive 3. The tray carrier unit 1 is guided by a guide shaft 4 and driven by a motor 7 through a pulley 6 and a belt 5. As seen from FIG. 8, the tray 8 is provided with a medium storage recess 9, an opening 10 in which a pickup 14 and a turn table 13 on the drive 3 can enter, positioning holes 11 for positioning of the tray relative to the drive 3, and a notch 12 by which the tray carrier unit 1 performs ejection/insertion of the tray from/in the magazine 2. Further, the drive 3 installed on the auto-changer is provided with a turn table 13 that rotates with a medium disposed on it, a pickup 14 that reads signals from the medium, and positioning pins 15 corresponding to the positioning holes 11 of the tray 8.
Next, the operation will be described. The tray carrier unit 1 is driven by the drive motor 7 through the belt 5 in the arrow a and b directions, moves to a position corresponding to a specified tray 8, and takes the tray 8 from the magazine 2 using the notch 12. Next, the tray carrier unit 1 having the tray 8 moves in the arrow a direction and performs positioning of the tray 8 relative to the drive 3 by fitting the positioning holes 11 of the tray 8 to the positioning pins 15 on the drive 3. At this time, the turn table 13 and the pickup 14 on the drive 3 enter in the opening 10 of the tray 8, centering of the medium disposed on the tray 8 is performed on the turn table 13, and the medium is fixed onto the turn table 13 by clamping means (not shown) constructed on the tray carrier unit 1. Thereafter, the turn table 13 rotates, and reading of signals is carried out by the pickup 14. In this state, the tray 8 is positioned by the drive 3 and held in the tray carrier unit 1 at such a height that it does not contact the medium.
The operation to return the tray 8 for which reproduction has ended will be performed as follows. When the turn table 13 stops, the tray carrier unit 1, which has been positioned by the drive 3, is moved in the arrow b direction by the drive motor 7. Thereby, clamping of the medium onto the turn table 13 is canceled, and the medium being disposed on the tray 8 is sent to a prescribed position of the magazine 2 and returned into the magazine 2 using the notch 12.
In the conventional structure mentioned above, however, the tray is not provided with means for detecting the kind of the medium, and the installed drive is either a drive for reproduction only or a drive for both recording and reproduction. Hence, it can deal with only one of a medium for reproduction-only and a medium for both recording and reproduction and, therefore, it is not applicable to an auto-changer using a mixture of reproduction-only media, such as CD-ROMs, and recordable and reproducible optical disk media, which media perform such as image processing that has attracted attention in recent years. Further, in an auto-changer using a single magazine, since recordable and reproducible optical disk media are sensitive to finger prints and flaws in handling, they cannot be used in a mixture in a magazine which is changeable freely by the user.